2017-12-01 / Health & Fitness

Healthy CHOICES: Not all smoothies are alike or healthy

SUSAN SUMMERTON, OD

You probably know that a smoothie is a beverage made from blended raw fruit or vegetables with other ingredients such as water, milk, ice, protein powder and sweeteners. Smoothies can be an easy, portable, custom-made and potent blend of good nutrition.

The fiber makes smoothies more healthful than fruit juice alone and the fluid-plus-fiber combination of a smoothie works to fill you up and maintain bowel health.

They can contain antioxidants to protect the body from damage caused by free radicals. The free radical molecules attack healthy cells and can cause the cells to die or to mutate. They can adversely alter lipids, proteins, and DNA plus trigger a number of diseases.

Smoothies are typically marketed to health-conscious people but the health benefits of a smoothie depend on its ingredients. When making one at home you can add all kinds of ingredients to achieve the health benefits. This can help you avoid a trap: Some commercial smoothies have added sugar, which can more than double their carbohydrate content.


Layered berry and chia seeds smoothies Layered berry and chia seeds smoothies Consider the satiety

When drinking a liquid smoothie as a meal there is the satiety effect of eating solid food versus liquid to consider. One published study compared the results in people who ate a solid fruit salad with raw apples, apricots and bananas, and had three cups of water to drink, with two cups of water added to the fruit and combined in a fruit smoothie, with participants also given one cup of water.

People in the study felt significantly less full after the smoothie even though both groups consumed the same amount of food and the same amount of fiber. In smoothie form, it just didn’t fill people up as much as eating the whole food did. Study authors speculated that the act of chewing itself may be a satiety signal.


Kale fruit smoothie Kale fruit smoothie However, another published study was conducted with soup, which essentially is a hot green smoothie of blended vegetables. And the soup proved more satiating than the same veggies in solid form. The difference in the two study results probably shows the impact of the time it takes to consume food and that feelings of hunger and fullness are subjective.

Eating more slowly has been shown to reduce calorie intake. People tend to report hunger more in accordance with how many calories they think something has rather than the actual caloric content. In the study known as “Mind Over Milkshakes,” people were offered two milkshakes, one described as indulgent, the other sensible. The results showed people have different hormonal responses to them, even though the milkshakes were the same — only the descriptions were different.

Blending breaks cell walls

Blending fruits and vegetables breaks the cell walls to help digestive efficiency and absorb nutrients. The cell walls can contain carotenoid phytonutrients, like beta carotene and lycopene. Results can differ when fruits are liquefied in regard to blood sugar reaction and also may be affected by how much is consumed and how quickly.

For example, consuming blended apples has been shown to cause a hypoglycemic dip compared with eating the whole apple.

Drinking blended berries improved blood sugar control, likely due to special phytonutrients that may slow sugar uptake into the bloodstream. In a study in Journal of Nutrition, six weeks of blueberry smoothie consumption improved whole body insulin sensitivity. Compared with 40 other fruits and vegetables measured for their antioxidant activity, the U.S. Department of Agriculture has ranked blueberries far and away the best.

The bottom line is that unhealthy lifestyle behaviors are associated with increased risk of premature death. These bad habits include not eating enough quality nutrition, especially greens. The best way to get your greens is in whichever way you’ll eat the most of them, and one way to sneak extra greens into your daily diet is with whole food smooth­ies. Adding a little fruit will help mask the bitterness of the greens.

Moderation in this, too

Keep in mind that just like anything, you don’t want to overdo it. Green drinks with large quantities of raw, leafy green vegetables facilitate an initial detoxification process that makes a person feel great but they also can have high oxalate levels. There is some evidence that a high oxalate diet can contribute to some very serious health problems, particularly if you are one of the 20 percent of people with a genetic tendency to produce oxalates or if you suffer from candida or other fungal challenge.

Smoothies can be made in less than five minutes, making them hands down one the healthiest fast foods. They are an easy way to get five or more servings of fruits and vegetables every day. You can get creative and add your own choice of ingredients or search online for delicious recipes.

The information in this column is not a substitute for professional medical advice.

Susan Summerton, O.D., is a board-certified optometrist at Tyson Eye, a certified nutrition specialist and an adjunct professor of nutrition at Hodges University. She can be reached at su­san.summerton@tysoneye.com.tysoneye.com.

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